This application claims the priority of German Application No. 101 07 282.1 filed Feb. 16, 2001, which is incorporated herein by reference.
This invention relates to a device and method for detecting lightweight waste such as short fibers, dust, fiber fragments, fly and the like in a carding machine. Such waste is released from the fiber material while being processed by a clothed fiber processing roll. The waste is carried away in a suction conduit containing a filter.
In a known apparatus, such as disclosed, for example, in German Patent No. 34 29 024 the dust and dirt content of the fiber material is measured. The fiber material is advanced by a feeding device to an opening roll which cooperates with a dust separating opening provided with a sieve-like surface adjoined by a filtering unit which, as viewed in the direction of the flow of the suction stream, comprises a sieve for short fibers and fly and a dust filter. After performing a test, the proportion of dust (at the dust filter) and short fibers (at the sieve) may be determined by measurements. It is a disadvantage of such a prior art arrangement that the degree of the intensity of fiber opening performed by the opening roll remains unchanged. It is a further drawback that the measuring and evaluating steps are intermittent which is a structurally complex solution.
It is an object of the invention to provide an improved device and method of the above-outlined type from which the discussed disadvantages are eliminated and which, in particular, make possible a continuous determination of the fiber damages as a result of the degree of aggressiveness of the carding operation.
This object and others to become apparent as the specification progresses, are accomplished by the invention, according to which, briefly stated, the carding machine includes clothed rolls for processing and carrying fiber material thereon; an arrangement for separating lightweight waste from the fiber material processed by the clothed rolls; a conduit for receiving the lightweight waste; an air stream generating arrangement for generating an air flow in the conduit for removing the lightweight waste; an adjusting device for varying a degree of carding intensity of the carding machine; and a detecting device for measuring quantities of the lightweight waste produced at a respective degree of carding intensity.
By virtue of the invention, the degree of fiber damage to the carded fiber material (aggressiveness of carding) can be continuously (on-line) determined. It is a particular advantage of the invention that the degree of fiber damage in a given carding operation, as concerns the quantity of light waste, may be compared with measured values for the damaged fiber in case of gentle carding and in case of aggressive carding and to derive an optimal setting for the carding process from these findings.